1. Technical Field of the Invention
The present invention relates to an oil filling nozzle having a means for recovering vapor generated in oil filling services.
2. Description of the Related Art
In case that highly-volatile fuel such as gasoline is fed to a fuel tank of an automobile, large quantities of vapor generate and are released into the atmosphere, which increases a risk of inflammability and causes an environmental pollution.
On the other hand, recovery rates of devices for recovering the vapor differ in each countries (100%±5% in Europe, 100%-120% in China), and adjustment of the recovery rate is performed by changing cross-sectional area of a vapor passage.
In addition, as described in the Patent Document 1, a diaphragm valve is connected to a vapor passage in order that the recovery rate becomes constant in a wide flow rate range, and the diaphragm valve is controlled to be opened and closed by liquid pressure in a nozzle main body.
However, the adjustment of the recovery rate is determined by elasticity of the diaphragm valve itself, so that the adjustment is effectual in certain flow rate, but the recovery rate varies with the flow rate when the recovery rate is changed from 120% (the line A in the FIG. 8) to 100% (the line B in the FIG. 8).
The content of Japanese Patent Application Publication No. 2004-142812 is incorporated herein by reference in its entirety.